This invention relates to the generation of electrical power by piezoelectric generators, and particularly to the protection of such generators against excessive strains during use.
U.S. Pat. No. 4,685,296, to Burns, the subject matter of which is incorporated herein by reference, discloses a piezoelectric power generating system comprising a float on a surface of a body of water, e.g., an ocean, and a piezoelectric power generator suspended from the float and anchored, under tension, to the ocean floor. The generator is alternately strained and destrained in response to up and down movements of the float in response to passing waves and generates electrical power in relation to the range of such straining and destraining.
For maximum power generating capacity, the system is preferably designed such that the range of straining during normal use is close to the maximum allowable straining of the generators without damage. The range of straining is a function of the heights of the passing waves, and in conditions of unusually high waves, a danger exists that the piezoelectric elements are over strained and damaged. Accordingly, a need exists for preventing, preferably completely automatically and instantaneously, excessive straining of the piezoelectric generator in response to waves of excessive heights.